Abstract

Stress responses can be functional adaptions to help individuals cope with hassles by changing physiological processes during stressful episodes. In contrast, inadequate or excessive or too brief or prolonged stress responses can be harmful to the organism as stress has been shown to negatively impact on mental and physical health in the long term. Exposure to a stressor alters numerous biological functions with the hypothalamic-pituitary-adrenal axis and the autonomous nervous system accounting to the major human biological stress system. Research on the effects of pharmacological as well as psychological interventions often used the standardized psychosocial stress test named Trier Social Stress Test to reliably induce acute stress in a laboratory setting in the major human stress systems. The emphasis of the current dissertation was to investigate two different interventions aiming to reduce physiological and emotional stress responses to the Trier Social Stress Test. Therefore, the thesis had two objectives: one was to examine the effects of the fixed herbal drug combination Ze 185 in men on stress responses of the hypothalamic-pituitary-adrenal axis and self-reported anxiety (Study I, Publication I) and of the autonomous nervous system (Study I, Publication II). The second goal was to investigate the effects of a social support stress management on stress responses in women assessing parameters of the hypothalamic-pituitary-adrenal axis, self-reported anxiety, and the autonomous nervous system (Study II, Publication III). For this reason, basic research approaches with healthy participants undergoing the Trier Social Stress Test and psychophysiological methods were chosen and applied in two randomized controlled studies. The first study revealed that the participants receiving the fixed herbal drug reported reduced anxiety in comparison with the placebo (p = .03) and no treatment groups (p = .05) in response to the stress test while there were no significant differences in the biological stress response of the hypothalamic-pituitary-adrenal axis assessed with cortisol (p = .97; Study I, Publication I). In line with this, the parameters of the autonomous nervous system namely salivary alpha amylase (p = .51), heart rate (p = .17), heart rate variability (p = .56), skin conductance level (p = .18), and skin temperature (p = 0.65) did not differ significantly in the three study groups (Study I, Publication II). The second study revealed no significant differences in cortisol (p = .78), heart rate (p = .49), and heart rate variability (p = .53) levels in response to the stress test between the two conditions while participants in the social support stress management showed condition showed a significantly attenuated integrated self-reported anxiety response (p = .03) in comparison to those in the control condition. In the second study participants in the social stress management and the waitlist control condition did not differ in their cortisol (p = .78), heart rate (p = .49), and heart rate variability (p = .53) reactions over time in response to the Trier Social Stress Test. Participants in the social support stress management showed a significantly attenuated integrated state anxiety response (p = .03) in comparison to those in the control condition. Both the fixed herbal drug combination and our social support stress management interventions attenuated the subjective emotional stress response in healthy participants and maintained the biological reactions in response to the standardized psychosocial stress test. However, as stress is a part of our daily lives, it is important to investigate and develop interventions supporting individuals to cope with stress to increase well-being during challenging episodes.